RF communications transmitters, especially in the military, use broadband power amplifiers and conventional mixers to translate phase modulated intermediate frequencies (IFs) to the desired radio frequency (RF). However, future trends in radio production, and especially the military, are to use phase locked loops (PLLs) in the power amplifier chain from the IF to RF, to band limit the noise power radio output to the phase locked loop bandwidth. The phase locked loop power amplifier is not compatible with previous BPSK and QPSK modulators because the output of these modulators has a tendency to collapse to zero in certain situations, whereupon the phase locked loop power amplifier drops out of the locked mode of operation. This loss of lock in the phase locked loop power amplifier can be a serious problem.